Field of the Invention
The present invention relates to location information of a local area network in a cellular communications network system when the local area network provides wireless access to a core network of the cellular communications network system.
Related Background Art
The following meanings for the abbreviations used in this specification apply:
3GPP third generation partnership project
AAA authentication, authorization, accounting
AF application function
AVP attribute value pair
CC contents of communications
CDR charging data record
CG charging gateway
CGI cell global identifier
ECGI E-UTRAN CGI
E-UTRAN evolved universal terrestrial radio access network
ePDG evolved packet data gateway
GGSN gateway GPRS support node
GPRS general packet radio service
GTP GPRS tunneling protocol
GW gateway
IMS IP multimedia system
IP internet protocol
IRI intercept related information
LAI location area identifier
LIG lawful interception gateway
MAC medium access control
OCS online charging system
PCRF policy charging and rules function
P-CSCF proxy call session control function
PDN packet data network
PGW packet GW
PMIP proxy mobile IP
R release
RAI routing area identifier
SAI service area identifier
SSID service set identifier
TAI tracking area identity
UE user equipment
ULI user location information
v version
WLAN wireless local area network
In a cellular communications network system, operators are interested in using WLAN(s) as complementary access and in offloading selected users from the cellular communications network system to WLAN(s). Commonly, it is desired to connect a WLAN access to an operator's core network of the cellular communications network system. This way, core functionalities (e.g. policy enforcement, charging, lawful interception, etc.) become available for WLAN access.
Currently there is an interest in a trusted WLAN access which is under standardisation in 3GPP R11. From the architecture point of view, there is an access GW between the trusted WLAN access and a PGW. The access GW is connected to the PGW via an interface S2a. GTP based S2a is currently under standardisation in 3GPP R11. In addition, there is a solution to use an interface Gn for connecting an access GW and a GGSN.
There is also an interest in an untrusted WLAN access. From the architecture point of view, there is an ePDG between the untrusted WLAN access and the PGW. The ePDG is connected to the PGW via an interface S2b. GTP based S2b is standardised in 3GPP R10.
It is to be noted that it is also possible to use PMIPv6 on the interfaces S2a, S2b. Location information is not available for GTP based S2a nor GTP based S2b, and neither for the Gn interface nor for PMIPv6 based S2a. Location information is needed in the PGW/GGSN for multiple purposes, e.g. for policy enforcement, charging and lawful interception.